Plenty of new housing needs to be built in Northern Virginia over the next few decades to keep up with expected job growth, but for now some of it won't include built-in sprinkler systems. This week, the Virginia Board of Housing and Community Development voted against an update to the Commonwealth's construction code that would have required that sprinklers be put in all new single-family homes and townhouses. Federal law already requires most larger commercial and retail buildings have sprinkler systems. Home-builders hailed the 10-4 vote taken Monday, saying that requiring sprinklers would only throw another obstacle in the way of the new housing construction that is needed to help close what officials say is a 75,000-home gap between what's currently expected to be built across the region and what's actually needed to keep pace with estimated job growth.